believe it or not There is no getting rid of big base it is actually of the most important base for Pakistan and has a load of capability, my friend you can put an air base in the middle of chagai and in 5 years it will turn into a population. Air bases attract business in Pakistan/all over the world.I believe bases in Balochistan will protect the civil population too because in war they are going to be targeted. The bases in Karachi right now are very very close to civilians. Which is a threat to the civilians and the armed forces. We're all aware of the terrorist attacks on airforce bases.
I know there is one in Omera if im not mistaken but that is too far. I believe J-15s should be near karachi but not in Karachi. Thus their radius can be fully utilized.
Base in Baluchistan will not be feasible for defensive ans PAF is highly concentrated on defensive and has recently build up it's offensive capability and a very good one indeed. Infrastructure will also be a very big problem.
On the contrary FCU Training base can be moved to somewhere in south KPK or north Baluchistan with some offensive capability.
Multan can be upgraded heavily and there is potential
Risalpur/Mardan has an even better potential for both offensive and defensive operation's